Pressure Sensing Operation of SWCNT Network Thin Films

Abstract

Carbon nanotubes (CNTs) have outstanding mechanical, thermal and electrical properties that make them suitable for a wide range of sensor applications. In this report, we fabricated Single-walled carbon nanotube (SWCNT) network thin films on patterned Si substrates and demonstrated the possibility of using CNTs as pressure sensors. The SWCNT network films were made by the vacuum filtration method. Well dispersed suspension of SWCNT was filtered onto an anodic aluminum oxide (AAO) membrane and transferred to the patterned Si substrates that were fabricated by optical lithography. Then, we spin-coated a layer of poly dimethy siloxane (PDMS) on the patterned SWCNT network films. We monitored the conductance changes due to the applied vertical pressures on the patterned thin film sensors with different density of the SWCNTs. We also investigated the response time and repeatability as well as the sensitivity of the SWCNT network pressure sensors.